Tamperproof cap closure

ABSTRACT

A roll-on-type cap closure having an improved tamperproof feature wherein the cap closure is characterized by its ease of removal from the container to which it is threadibly engaged incident to providing the authorized user with excellent tactual, audible, and physical indications of whether the cap closure has or has not been previously subjected to tampering.

United States Patent lnventor Charles N. Hannon 27 Sargent Road, Scarsdale. NY. 10510 Appl. No. 836,838

Filed June 26, 1969 Patented June 29, I971 TAMPERPROOF CAP CLOSURE 9 Claims, 9 Drawing Figs.

U.S. Cl 215/42 Int. Cl t. B65d 41/20 Field ofSearch 215/4239. 43, 46

[56] References Cited UNITED STATES PATENTS 3,303,955 2/1967 Osborne et al 215/42 3,465,907 9/1969 Dorn et al 215/42 Primary Examiner-George T. Hall AtI0rney-D0nald P. Gillette ABSTRACT: A rolI-on-type cap closure having an improved tamperproof feature wherein the cap closure is characterized by its ease of removal from the container to which it is threadibly engaged incident to providing the authorized user with excellent tactual, audible, and physical indications of whether the cap closure has or has not been previously subjected to tampering.

PATENTEU Jlmesusn 3,589,544

sum 1 BF 2 F INVENTOR.

PATENTED JUN29 I97! SHEET 2 OF 2 INVENTOR. CHARLES M Maw/v0 TAMPERPROOF CAP CLOSURE SUMMARY OF THE INVENTION threads on the outside surface of the neck of a rigid container,

usually glass. The roll-on cap closure is supplied to the user as a smooth-skirted (unthreaded) cap that is placed over the sealing area of the container. Then, under controlled top pres-- sure, the skirt is pressed against the threads of the neck of the rigid container by a rotating head equipped with rolls that press the metal with sufficient force to make it conform to the finish of the container, thus forming threads on the skirt and producing a cap closure which is threadibly engageable about the mouth of the rigid container.

The roll-on cap closure may be rendered tamperproof by elongating the skirt to include an extension which is circumferentially crimped under a shoulder encircling the mouthdefining wall of the container below the threaded portion of the container. This feature of the assembly requires the user to rupture the skirt in the process of unscrewing the cap closure from the neck of the container.

Although enjoying wide acceptance, tamperproof cap closures of the above description have a pronounced impediment in that an excessive amount of manual torque must be applied to the cap closure to rupture the skirt incident to unthreading the cap for removal. As an improvement toward facilitating removal of the roll-on cap closure while still retaining the tamperproof feature, the skirt of the closure has been, in the prior art, circumferentially scored, perforated,- or otherwise weakened in the area below the threaded portion to provide an incipient line of rupture encircling the skirt. An example of such prior art is described in US. PaT. No. 3,348,7 l8.

In the art of constructing the tamperproof roll-on cap closures of the above description, the score line or line of perforations forming a weakening line encircling the elongated skirt is formed during the fabrication of the cap closure and is incorporated in the smooth-skirted (unthreaded) cap before the cap is placed over the sealing area of the container and crimped about the threads and shoulder of the rigid container. Understandably, the process of crimping the skirt of the cap closure, during which the metal of the skirt is sequentially pressed against the threads of the rigid container and then indented beneath the shoulder of the container below the threads by means of a series of rollers, induces severe deformation of the skirt metal and, in the course of the operation, the circumferential score or line of perforations is subject to strain and rupture. Therefore, it has been, by necessity, the practice of the prior art to limit the degree to which the skirt is weakened in order to avoid rupturing the skirt either partially or completely during the application of the cap closure to the container and thus destroying the tamperproof condition of the cap closure. By so doing, the cap closures, prior to my in vention, have retained, to a considerable degree, the disadvantage of requiring excessive manual torque to remove the cap from the container.

It is, therefore, a principal object of this invention to provide a tamperproof cap closure of the roll-on type which requires a minimum amount of hand torque to rupture the sealing element incident to unscrewing the cap closure for removal from the container.

It is a major object of the invention to provide a tamperproof cap closure of the roll-on type which exhibits sufficient restraint to rupture of the sealing element incident to removal of the cap closure to the extent only of providing adequate tactual indication that the seal has not been previously ruptured.

It is an object of the invention to provide a roll-on-type cap closure which, by visual observation, readily reveals whether the cap closure has or has not been previously partially or completely removed from the container.

It is another object of the invention to provide a roll-on-cap closure having a tamperproof feature which exhibits audible indication to the authorized user that the cap closure has not been previously subjected to tampering.

It is a feature of the invention to provide a method of constructing a roll-on-type cap closure and a method of installing the cap closure on a container which assures complete integrity of the cap closure while still providing a tamperproof feature which requires minimum effort on the part of the user to utilize incident to removing the cap closure from the container.

It is another feature of the invention to provide a cap closure of a tamperproof roll-on construction which is adapted to incorporate a pliable sealing disc to adequately seal the opening of the container to which the cap closure is applied.

It is still another feature of the invention to provide an improved tamperproof cap of the roll-on type which incorporates the prior art advances in construction features including the employment of knurling on the skirt to facilitate manual gripping.

The aforementioned objects and features of the invention are accomplished by a novel method of fabricating the circumferential line of weakening about the skirt of the cap closure. The essence of my invention resides in forming the line of weakening by two separate operations wherein the initial step in the construction of the tamperproof feature takes place prior to applying the cap closure to the mouth of the container and the final operation takes place after the cap closure has been rolled onto the threads of the rigid container. It is this combination of construction operations, before and after application of the cap closure to the container, which provides a closure with an effective tamperproof feature which uniquely exhibits tactual, audible, and visual indication of no previous unauthorized use of the cap closure and yet offers only a slight additional restraint to the removal of the cap closure incident to unthreading it from the container.

Essentially, the invention involves forming a weakening line circumferentially about the skirt of the cap closure prior to applying the cap closure to the container sufficiently strong to withstand rupture during the roll-on application of the cap closure to the container followed by a second operation which involves reducing the strength of the weakening line to the point where it provides integrity to the skirt but can be ruptured with a minimum of manual torque on the part of the user.

The foregoing and additional objects and features of this invention will become more fully apparent from the following detailed description of the construction of the cap closure and its application to a container when taken in consideration with the figures of the drawing wherein like reference characters are employed to designate like parts in the specification and throughout the several views.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of the cap closure prior to application to the container.

FIG. 2 is an enlarged perspective view of a portion of the cap closure detailing the structure of the bridges connecting the skirt of the cap closure and the skirt lower extension.

FIG. 3 is an enlarged plan view of a portion of the cap closure detailing a preferred embodiment of the bridge structure wherein the bridges are deformed into substantially channel shape members connecting the skirt and the skirt lower extension.

FIG. 4 is an enlarged plan view similar to that of FIG. 3 but showing an alternate version of the configuration of the bridge members wherein they are semicircular in shape.

FIG. 5 is an enlarged perspective view of a portion of a cap closure showing another construction of the bridge members connecting the skirt of the cap closure to the skirt lower extension.

FIG. 6 is a sectional view of the cap closure when partially applied to the container.

FIG. 7 is a sectional view of the cap closure applied to the container.

FIGS. 8 and 9 are greatly enlarged views of cap closure bridge members which have been structurally weakened by controlled impact.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Throughout the description of the preferred embodiments of this invention, the operation of preforming" is directed to those steps in the construction of the cap closure which take place prior to the application and assembly of the cap closure onto the rigid container.

Referring to FIG. 1, the cap closure 8 of this invention is illustrated in the form as it appears before installation onto a container. The cap closure is fabricated of deformable, ductile material and is commonly classified as a roll-on-type closure. The preformed closure may be considered as being comprised of four major portions wherein a flat circular top panel 10 has depending along its periphery an annular smooth surfaced skirt l2 and a lower skirt extension 14, also smooth surfaced, connected to the skirt by a plurality of narrow bridges l6 uniformly spaced circumferentially about the skirt and the skirt lower extension. The plurality of bridges 16 connect the skirt 12 of the cap closure 8 with the lower skirt extension 14 and, in effect, serve to interrupt an otherwise continuous circumferential, horizontal cut in the cap closure material separating the skirt from the skirt lower extension. This feature of the invention may be better observed in the enlarged view of FIG. 2.

The configuration of the preformed bridges is critical to the invention. Preferably, as illustrated in FIG. 3, the bridges shown in enlarged view are formed so as to project outwardly from the periphery of the smooth surfaces of the skirt and the skirt lower extension. The formation of the bridges may be ac complished by one of several methods such as by deforming the ductile metal of each bridge into a small substantially channel-shape member, as illustrated in FIG. 3, with an outward web portion 16A integrally attached to the radially projecting flange portions 168 of the bridge.

Alternatively, the bridges may be preformed into the shape of semicircular members with the bight portion 16C of the curved surface projecting outwardly from the surfaces of the smooth skirt and the smooth skirt lower extension. This method of construction is illustrated in FIG. 4.

The outwardly projecting bridge members may also be preformed by indenting the abutting edges of the skirt and lower skirt extension as an ancillary operation to making the interrupted horizontal circumferential cut 20 in the cap closure material. This method of preforming the bridge members is shown in FIG. 5.

Regardless of the manner in which the bridges are preformed and, regardless of their shape, it is essential to the invention that the bridges be of sufficient number and strength to resist rupture incident to the application of the cap closure to the container as will be described hereinafter. Also, it is important to the invention that the bridges be configurated so as to be adaptable to physical deformation subsequent to that which the skirt and skirt lower extension undergoes as the cap closure is pressed or rolled onto the mouth defining wall ofthe container. Preferably the bridges should be configurated to project slightly outwardly from the smooth surfaces of the skirt and the skirt lower extension in order to facilitate their physical deformation subsequent to applying the cap closure to the container.

FIG. 6 shows the cap closure 8 partially assembled onto the outer surface of the neck of a rigid container 18. As shown,

the previously smooth skirt 12 has been rolled or pressed against the threads 18A on the outer surface of the neck of the rigid container. This rolling or pressing operation is accomplished with sufficient force to deform the skirt portion 12 of the cap closure and have it conform to the finish of the container. In effect, the skirt portion is deformed into a threaded configuration conforming to the threads of the container and is, therefore, threadably engaged to the container. It is to be observed that at this stage of the application of the cap closure to the container, the threads of the cap closure are tightly engageable with the threads of the container neck and rotation of the cap closure for further tightening is restrained. The rolling-on or pressing of the skirt 12 about the threads 18A of the container is accomplished in two rolling operations which occur sequentially. This division of rolling operations is necessary because the ductile metal of the skirt undergoes a certain amount of circumferential movement incident to being pressed or rolled into thread formation. Forming the threads in two steps beginning at the top of the skirt in proximity of the top panel 10 permits the lower section of the skirt 12 to move circumferentially in the direction of the rolling-on movement and thereby permits the ductile metal to be deformed without rupture. Accordingly, as the second and final step of the thread forming operation is accomplished, the skirt lower extension 14 is free to continue circumferential movement about the neck ofthe container.

As shown in FIG. 7, the next step in the operation of applying the cap closure to the container is that of indenting the skirt lower extension margin 14A beneath the shoulder 22 of the container circumferential about the neck or mouth-defining wall of the container at a point below the threaded portion 18A of the mouth-defining wall of the container. The operation whereby the skirt lower extension margin 14A is indented beneath the shoulder encircling the neck of the container 18 is also accomplished with a circumferential rolling of the metal of the skirt lower extension into place beneath the shoulder 22 encircling the neck of the container. Although this final rolling operation induces less circumferential movement than in the two previous rolling operations of forming the threads, since there is less skirt lower extension metal free to move and thus become distorted, it is to be observed that the bridges 16 connecting the skirt and the skirt lower extension will assume the major burden of the distortion. It is essential, therefore, that the bridge members be designed both as to construction and number so as to be structurally sufficient in strength to sustain, without rupture, the degree of distortion inherently associated with the step of rolling the metal of the skirt lower extension margin 14A into place beneath the shoulder encircling the mouth-defining wall of the container for securement thereon.

As with the prior art constructions, the minimum structural strength tolerances of the bridge members to rupture is, in this invention, exceeded by design in order to assure assembly of the cap closure with the skirt 12 integral with the lower skirt extension 14. This is necessary because of the variations in the ductility and strength of the metal of which the cap closure is made and the variations in the degree of torque and resultant distortion of the bridge member metal accompanying the rollon pressing application of the cap to the mouth-defining wall of the container. Since it is not practical to accurately measure the capacity of each bridge member to sustain a range of distortional forces, it is imperative, in order to maintain satisfactory quality control conditions of cap closure assemblies, to have the bridge members overdesigned as to structural strength.

As can be readily appreciated, the condition of excessive strength in the bridge members will result in a cap closure which, while having the important tamperproof feature wherein the skirt must be broken away from the secured skirt lower extension incident to unthreading the cap closure for removal from the container, will require an amount of hand torque to unscrew the cap closure and rupture the bridge members unnecessarily greater than if the bridge members were formed with only adequate minimum structural strength to maintain integrity of the assembled cap closure.

In contrast to the prior art, wherein the application of the roll-on tamperproof cap closure to the container is complete when the skirt lower extension margin is crimped for securement beneath the shoulder encircling the mouth-defining wall of the container, my invention involves an additional operation in which the structural strength of the bridge members 16 is diminished to an extent whereby the bridge members maintain skirt l2 attachment to the skirt lower extension 14 but are weakened to the degree of offering a minimum of breaking resistance incident to removal of the cap closure commensurate with adequate tactual, audible, and visible indications of whether or not the cap closure has been previously subjected to tampering.

This additional operation in the assembly of the cap closure to the container involves partially cutting, nicking, filing, or upsetting the ductile material of the bridge members to reduce the structural strength thereof to a satisfactory minimum as described above. Recent developments have led to a practical method of automatically accomplishing the operation of weakening the bridge member material by incorporating an additional element for this purpose onto the rotating head employed to press the cap closure to the container finish. The rotating element for deforming the bridge members can be accurately adjusted to contact each bridge member with sufficient impact to impart the desired controlled extent of deformation thereof.

Illustrative examples of bridge members showing the structurally weakened condition after being subjected to the abovedescribed impact operation are shown in F IGS. 8 and 9.

The novel design of the preformed cap closure wherein the bridge members are configurated to cooperate with a practical automatic machine to effect controlled weakening thereof results in an improved tamperproof cap closure for sealing the contents of a container. importantly, the objects of the invention are accomplished with only a slight incremental cost compared to the cap closures of the prior art and the embodiments of the invention, therefor, are commercially attractive.

As will be readily understood by those skilled in the art, the cap closures of this invention may be featured with knurling 23 as shown in FIG. I to facilitate hand gripping for unthreading the cap. Also, as shown in FIG. 6 the cap closures may be adapted to accommodate a sealing disc 24 of resilient material beneath the top panel for the purpose of insuring a tight seal of the container mouth.

While the foregoing has illustrated and described what is now contemplated to be the best mode of carrying out the invention, the constructions are, of course, subject to modification without departing from the spirit and scope of the invention. It is not desired, therefor, to restrict the invention to the particular forms of construction illustrated and described, but to cover all modifications that may fall within the scope of the appended claims.

Having described my invention, what I claim as new and desired to be secured by Letters Patent is:

l. In a tamperproof cap closure of ductile material adapted for application to the threads on the outside surface of the mouth-defining wall of a rigid container, said cap closure having a circular top panel adapted to seal the mouth of said container and a skirt integral with and depending from the periphery of said top panel and adapted for threadable engagement with the threads of the mouth-defining wall of the container, said skirt having a lower extension, the margin thereof circumferentially indented beneath a shoulder encircling the mouth-defining wall of the container below the threaded portion for securement thereon; the improvement comprising a plurality of narrow bridge members spaced apart and deformed on the outside surface of the mouth-defining wall of the container whereby the intact deformed bridge members offer minimal rupture resistance to effect separation of the skirt from the lower extension incident to unscrewing the cap closure for removal from the container.

2. In combination with a rigid container, the cap closure set forth in claim 1 wherein said bridge members are structurally weakened subsequent to applying1 the ca closure to the threads on the outside surface of t e mout -defimng wall of said rigid container and subsequent to circumferentially indenting the margin of the lower extension beneath the shoulder encircling the mouth-defining wall of the container below the threaded portion for securement thereon.

3. In combination with a rigid container, the cap closure set forth in claim 1 wherein said bridge members are structurally weakened subsequent to applying the cap closure to the threads on the outside surface of the mouth-defining wall of said container and coincidentally to circumferentially indenting the margin of the lower extension beneath the shoulder encircling the mouth-defining wall of the container below the threaded portion for securement thereon.

l. The cap closure set forth in claim 1 wherein each of said narrow bridge members is shaped substantially in a channellike configuration having parallel flange portions radially projecting outwardly of the surface of the skirt and the surface of the lower extension and interconnected by a web portion.

5. The cap closure set forth in claim 1 wherein each of said narrow bridge members is shaped substantially in a semicircular configuration having the bight of the curved bridge member projecting outwardly of the surface of the skirt and the surface of the lower extension.

6. The cap closure set forth in claim 1 wherein said narrow bridge members are horizontally scored subsequent to applying the cap closure to the threads on the outside surface of the mouth-defining wall of the container.

7. The cap closure as set forth in claim 1 wherein a portion of the material of each of the said narrow bridge members is removed by filing subsequent to applying the cap closure to the threads on the outside surface of the mouth-defining wall of the container.

8. The cap closure as set forth in claim 1 wherein a portion of the material of each of the said narrow bridge members is removed by a cutting operation subsequent to applying the cap closure to the threads on the outside surface of the mouthdefining wall of the container.

9. The cap closure set forth in claim 1 wherein a portion of the material of each of said bridge members is upset subsequent to applying the cap closure to the threads on the outside surface of the mouth-defining wall of the container. 

1. In a tamperproof cap closure of ductile material adapted for application to the threads on the outside surface of the mouthdefining wall of a rigid container, said cap closure having a circular top panel adapted to seal the mouth of said container and a skirt integral with and depending from the periphery of said top panel and adapted for threadable engagement with the threads of the mouth-defining wall of the container, said skirt having a lower extension, the margin thereof circumferentially indented beneath a shoulder encircling the mouth-defining wall of the container below the threaded portion for securement thereon; the improvement comprising a plurality of narrow bridge members spaced apart and deformed on the outside surface of the mouthdefining wall of the container whereby the intact deformed bridge members offer minimal rupture resistance to effect separation of the skirt from the lower extension incident to unscrewing the cap closure for removal from the container.
 2. In combination with a rigid container, the cap closure set forth in claim 1 wherein said bridge members are structurally weakened subsequent to applying the cap closure to the threads on the outside surface of the mouth-defining wall of said rigid container and subsequent to circumferentially indenting the margin of the lower extension beneath the shoulder encircling the mouth-defining wall of the container below the threaded portion for securement thereon.
 3. In combination with a rigid container, the cap closure set forth in claim 1 wherein said bridge members are structurally weakened subsequent to applying the cap closure to the threads on the outside surface of the mouth-defining wall of said container and coincidentally to circumferentially indenting the margin of the lower extension beneath the shoulder encircling the mouth-defining wall of the container below the threaded portion for securement thereon.
 4. The cap closure set forth in claim 1 wherein each of said narrow bridge members is shaped substantially in a channellike configuration having parallel flange portions radially projecting outwardly of the surface of the skirt and the surface of the lower extension and interconnected by a web portion.
 5. The cap closure set forth in claim 1 wherein each of said narrow bridge members is shaped substantially in a semicircular configuration having the bight of the curved bridge member projecting outwardly of the surface of the skirt and the surface of the lower extension.
 6. The cap closure set forth in claim 1 wherein said narrow bridge members are horizontally scored subsequent to applying the cap closure to the threads on the outside surface of the mouth-defining wall of the container.
 7. The cap closure as set forth in claim 1 wherein a portion of the material of each of the said narrow bridge members is removed by filing subsequent to applying the cap closure to the threads on the outside surface of the mouth-defining wall of the container.
 8. The cap closure as set forth in claim 1 wherein a portion of the material of each of the said narrow bridge members is removed by a cutting operation subsequent to applying the cap closure to the threads on the outside surface of the mouth-defining wall of the container.
 9. The cap closure set forth in claim 1 wherein a portion of the material of each of said bridge members is upset subsequent to applying the cap closure to the threads on the outside surface of the mouth-defining wall of the container. 